Differences in the soil bacterial community under organic farming and conventional farming modes revealed by 16S rDNA sequencing
Background The bacterial communities is complex and different in various agricultural ecosystem. In this study, high-throughput Illumina MiSeq sequencing was conducted to assess the differences in soil bacterial communities between organic farming and conventional farming modes. Results A total of 3, 919 operational taxonomic units were identified and classified as 26 phyla, 42 classes, 78 orders, 120 families, 281 genera. The dominant genera were Lysobacter , Pseudomonas , Massilia ,
... obacter , Ferruginibacter , Flavobacterium , Flavisolibacter , Brevundimonas , Haliangium and Sphingomonas . Analysis of soil bacterial diversity showed that the soil under the organic farming had a greater bacterial diversity than that under the conventional farming. Linear discriminant analysis effect size analysis showed that the major bacterial groups identified in the soil sample CK1 (2015.4) and CK6 (2017.10) under conventional farming mode were largely different from those in the soil sample O6 (2017.10) under organic farming mode. Redundancy analysis demonstrated that available nitrogen was the most important factor regulating bacterial composition under the organic farming mode, followed by soil rapidly available phosphorous and potassium. Massilia , Pseudomonas , Lysobacter and Pseudarthrobacter abundances showed a strong positive correlation with the content of available nitrogen. Conclusions Organic farming could improve soil organic matter, available nitrogen, rapidly available phosphorus and retard soil acidification. This modification of soil can directly or indirectly relate to the bacterial communities in soil. The shifts of bacterial communities were complicated and dynamic with respect to all sorts of the measures of cultivation and management under organic farming mode.